diff options
| -rw-r--r-- | include/libuecc/ecc.h | 19 | ||||
| -rw-r--r-- | src/ec25519.c | 24 |
2 files changed, 28 insertions, 15 deletions
diff --git a/include/libuecc/ecc.h b/include/libuecc/ecc.h index 922ca22..a5f0df7 100644 --- a/include/libuecc/ecc.h +++ b/include/libuecc/ecc.h @@ -27,12 +27,6 @@ #ifndef _LIBUECC_ECC_H_ #define _LIBUECC_ECC_H_ -typedef struct _ec_public_key_xyz_256_work { - unsigned int X[32]; - unsigned int Y[32]; - unsigned int Z[32]; -} ec_public_key_xyz_256_work; - typedef struct _ec_public_key_256 { unsigned char p[32]; } ec_public_key_256; @@ -41,16 +35,19 @@ typedef struct _ec_secret_key_256 { unsigned char s[32]; } ec_secret_key_256; -typedef ec_public_key_xyz_256_work ec_25519_work; +typedef struct _ec_25519_work { + unsigned int X[32]; + unsigned int Y[32]; + unsigned int Z[32]; +} ec_25519_work; -void ec_25519_inflate(ec_25519_work *out, const ec_public_key_256 *in); -void ec_25519_deflate(ec_public_key_256 *out, ec_25519_work *in); +void ec_25519_load(ec_25519_work *out, const ec_public_key_256 *in); +void ec_25519_store(ec_public_key_256 *out, const ec_25519_work *in); void ec_25519_add(ec_25519_work *out, const ec_25519_work *in1, const ec_25519_work *in2); - void ec_25519_double(ec_25519_work *out, const ec_25519_work *in); - void ec_25519_scalarmult(ec_25519_work *out, const ec_secret_key_256 *n, const ec_25519_work *base); +void ec_25519_scalarmult_base(ec_25519_work *out, const ec_secret_key_256 *n); #endif /* _LIBUECC_ECC_H_ */ diff --git a/src/ec25519.c b/src/ec25519.c index 25ed1f6..effbfc6 100644 --- a/src/ec25519.c +++ b/src/ec25519.c @@ -25,7 +25,7 @@ */ /* - EC group operations for Twisted Edwards Curve ax^2 + y^2 + 1 + dx^2y^2 with + EC group operations for Twisted Edwards Curve ax^2 + y^2 = 1 + dx^2y^2 with a = 486664 d = 486660 on prime field p = 2^255 - 19. @@ -340,7 +340,7 @@ static void recip(unsigned int out[32], const unsigned int z[32]) { /* 2^255 - 21 */ mult(out, t1, z11); } -void ec_25519_inflate(ec_25519_work *out, const ec_public_key_256 *in) { +void ec_25519_load(ec_25519_work *out, const ec_public_key_256 *in) { int i; unsigned int X2[32], d_X2[32] = {0x04, 0x6d, 0x07} /* 486660 */, a_X2[32] = {0x08, 0x6d, 0x07} /* 486664 */, _1_a_X2[32], d_X2_a_X2[32], Y[32], Yt[32]; @@ -359,10 +359,10 @@ void ec_25519_inflate(ec_25519_work *out, const ec_public_key_256 *in) { square_root(Y, d_X2_a_X2); sub(Yt, zero, Y); - select(out->Y, Y, Yt, in->p[31] >> 7); + select(out->Y, Y, Yt, (in->p[31] >> 7) ^ (Y[0] & 1)); } -void ec_25519_deflate(ec_public_key_256 *out, ec_25519_work *in) { +void ec_25519_store(ec_public_key_256 *out, const ec_25519_work *in) { unsigned int x[32], y[32], z[32]; int i; @@ -454,3 +454,19 @@ void ec_25519_scalarmult(ec_25519_work *out, const ec_secret_key_256 *n, const e out->Z[i] = cur.Z[i]; } } + +static const ec_25519_work default_base = { + {0x51, 0x89, 0xfa, 0x46, 0xa0, 0xc0, 0x8b, 0x3d, + 0x30, 0x60, 0xf1, 0x7d, 0x2a, 0xec, 0xcd, 0xf3, + 0x24, 0x50, 0x96, 0x62, 0x21, 0xfc, 0xe6, 0x18, + 0x14, 0xd6, 0x11, 0xf8, 0x11, 0x91, 0xa1, 0x03}, + {0xf3, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x5f}, + {1} +}; + +void ec_25519_scalarmult_base(ec_25519_work *out, const ec_secret_key_256 *n) { + ec_25519_scalarmult(out, n, &default_base); +} |